Pension Plans, Postretirement and Other Employee Benefits - Plan Assets Using Fair Value Hierarchy (Details) - Pension Plans - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
U.S.
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	$ 1,145	$ 1,062	$ 995
U.S. | Level 1
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	882	817
U.S. | Level 1 | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	374	337
U.S. | Level 1 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	242	238
U.S. | Level 1 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	140	158
U.S. | Level 1 | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 1 | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	25	12
U.S. | Level 1 | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 1 | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 1 | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 1 | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	80	34
U.S. | Level 1 | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	21	38
U.S. | Level 2
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	52	42
U.S. | Level 2 | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	13	21
U.S. | Level 2 | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	39	21
U.S. | Level 2 | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 2 | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	17	21
U.S. | Level 3 | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	17	21
U.S. | Level 3 | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Level 3 | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Total
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	951	880
U.S. | Total | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	374	337
U.S. | Total | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	242	238
U.S. | Total | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	140	158
U.S. | Total | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	13	21
U.S. | Total | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	64	33
U.S. | Total | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Total | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
U.S. | Total | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	17	21
U.S. | Total | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	80	34
U.S. | Total | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	21	38
U.S. | Plan assets measured at net asset value
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	194	182
U.S. | Plan assets measured at net asset value | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	137	128
U.S. | Plan assets measured at net asset value | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	57	54
U.S. | Plan assets measured at net asset value | Government debt securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S.
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	571	523	$ 466
Non-U.S. | Level 1
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	64	70
Non-U.S. | Level 1 | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	1	1
Non-U.S. | Level 1 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	21	18
Non-U.S. | Level 1 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	12	23
Non-U.S. | Level 1 | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	10	6
Non-U.S. | Level 1 | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	14	5
Non-U.S. | Level 1 | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	1	3
Non-U.S. | Level 1 | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 1 | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 1 | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	5	14
Non-U.S. | Level 1 | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	261	234
Non-U.S. | Level 2 | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	42	58
Non-U.S. | Level 2 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2 | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2 | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	189	166
Non-U.S. | Level 2 | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	30	10
Non-U.S. | Level 2 | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2 | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2 | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 2 | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	113	80
Non-U.S. | Level 3 | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	113	80
Non-U.S. | Level 3 | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Level 3 | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Total
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	438	384
Non-U.S. | Total | Equity Securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	1	1
Non-U.S. | Total | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	63	76
Non-U.S. | Total | Fixed income securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	12	23
Non-U.S. | Total | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	10	6
Non-U.S. | Total | Government
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	203	171
Non-U.S. | Total | Real Estate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	31	13
Non-U.S. | Total | Insurance contracts
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	113	80
Non-U.S. | Total | Hedge funds
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Total | Cash and equivalents
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	5	14
Non-U.S. | Total | Real Estate And Other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	0	0
Non-U.S. | Plan assets measured at net asset value
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	133	139
Non-U.S. | Plan assets measured at net asset value | Equity securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	84	92
Non-U.S. | Plan assets measured at net asset value | Corporate and other
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	13	14
Non-U.S. | Plan assets measured at net asset value | Government debt securities
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items]
Net plan assets	$ 36	$ 33